This list of information technology companies is an approximate compilation of the largest such companies in Wayne, Oakland, Macomb, Washtenaw and Livingston counties that research, design, manufacture or invent equipment or software, plus companies that provide sophisticated computer services such as systems design, programming and information retrieval. It is not a complete listing but the most comprehensive available. Companies based elsewhere are listed with the address and top executive of their main Detroit-area office and are ranked by their revenue in the five-county area. Unless noted, the companies provided the information. Crain's estimates are based on industry analyses and benchmarks, news reports and a wide range of other sources. Actual revenue figures may vary. NA = not available.1
Formerly Compuware Corp's professional services divison2
Fiscal 2013.